A motor vehicle anti-lock braking system (referred to herein as an ABS system) repeatedly releases and re-applies hydraulic brake pressures during conditions of wheel lock to maximize the tractive force between the vehicle tires and the road surface. The pressure control is highly effective under most wheel lock conditions (referred to herein as “true ABS conditions”), but can actually extend the vehicle stopping distance under conditions where the wheel lock occurs due to wheel-hop when braking on a bumpy road surface. For this reason, most ABS systems not only detect insipient wheel lock, but also attempt to distinguish between true ABS conditions and wheel-hop conditions, so that ABS control is only initiated under true ABS conditions. A common method of distinguishing between true ABS conditions and wheel-hop conditions involves delaying the initiation of ABS control for a delay time; for example, the delay time may be determined based on vehicle deceleration so that a maximum delay occurs at low vehicle deceleration and a minimum delay occurs at high vehicle deceleration. However, it is difficult to reliably distinguish between true ABS conditions and wheel-hop conditions with such methods; for example, a similar response can occur for both a wheel-hop condition and a true ABS condition on a low coefficient of friction road surface. Accordingly, what is needed is a method of entering ABS control that reliably distinguishes between true ABS conditions and wheel-hop conditions, and that initiates ABS control without unnecessary delay under true ABS conditions.